Electronic Structure and Optical Properties of Solar Cell Materials CuAlX2 (X=S, Se)

The optical properties and electronic structure of solar cell materials CuAlX₂ (X = S, Se) have been investigated in this paper by using the state-of-the-art full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA) as implemented in Wien2k code. The exchange-correlation potential used in this calculation is Perdew-Burke-Ernzerhof (PBE). The optical properties such as dielectric tensor components and absorption coefficient of these materials are determined in order to investigate their usefulness as solar cell materials. Our calculations show that these compounds are direct band gap semiconductors. The optical absorption of solar radiations for CuAlSe₂ is investigated to be more in comparison of CuAlS₂ and hence is suggested as a useful solar cell material.